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author | AinsleySnow <772571228@qq.com> | 2024-04-03 19:45:50 +0800 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-04-03 07:45:50 -0400 |
commit | 52b18430ae105566f26152c0efc63998301b1134 (patch) | |
tree | 3ab2cf5026b41d2f93565c32f07ed48c371514c8 /llvm | |
parent | 51107be7dd7f83a107b9c35c39b16081e38f7a54 (diff) | |
download | llvm-52b18430ae105566f26152c0efc63998301b1134.zip llvm-52b18430ae105566f26152c0efc63998301b1134.tar.gz llvm-52b18430ae105566f26152c0efc63998301b1134.tar.bz2 |
[VP][DAGCombine] Use `simplifySelect` when combining vp.select. (#87342)
Hi all,
This patch is a follow-up of #79101. It migrates logic from
`visitVSELECT` to `visitVP_SELECT` to simplify `vp.select`. With this
patch we can do the following combinations:
```
vp.select undef, T, F --> T (if T is a constant), F otherwise
vp.select <condition>, undef, F --> F
vp.select <condition>, T, undef --> T
vp.select false, T, F --> F
vp.select <condition>, T, T --> T
```
I'm a total newbie to llvm and I'm sure there's room for improvements in
this patch. Please let me know if you have any advice. Thank you in
advance!
Diffstat (limited to 'llvm')
-rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 7 | ||||
-rw-r--r-- | llvm/test/CodeGen/RISCV/rvv/vselect-vp.ll | 53 |
2 files changed, 60 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 2f46b23..b889e4f 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -12056,6 +12056,13 @@ SDValue DAGCombiner::foldVSelectOfConstants(SDNode *N) { } SDValue DAGCombiner::visitVP_SELECT(SDNode *N) { + SDValue N0 = N->getOperand(0); + SDValue N1 = N->getOperand(1); + SDValue N2 = N->getOperand(2); + + if (SDValue V = DAG.simplifySelect(N0, N1, N2)) + return V; + if (SDValue V = foldBoolSelectToLogic<VPMatchContext>(N, DAG)) return V; diff --git a/llvm/test/CodeGen/RISCV/rvv/vselect-vp.ll b/llvm/test/CodeGen/RISCV/rvv/vselect-vp.ll index 0d52dd7..0a5e501 100644 --- a/llvm/test/CodeGen/RISCV/rvv/vselect-vp.ll +++ b/llvm/test/CodeGen/RISCV/rvv/vselect-vp.ll @@ -825,3 +825,56 @@ define <vscale x 2 x i1> @select_cond_x_cond(<vscale x 2 x i1> %x, <vscale x 2 x %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, <vscale x 2 x i1> %x, i32 %evl) ret <vscale x 2 x i1> %a } + +define <vscale x 2 x i1> @select_undef_T_F(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, i32 zeroext %evl) { +; CHECK-LABEL: select_undef_T_F: +; CHECK: # %bb.0: +; CHECK-NEXT: vmv1r.v v0, v8 +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> poison, <vscale x 2 x i1> %x, <vscale x 2 x i1> %y, i32 %evl) + ret <vscale x 2 x i1> %a +} + +define <vscale x 2 x i1> @select_undef_undef_F(<vscale x 2 x i1> %x, i32 zeroext %evl) { +; CHECK-LABEL: select_undef_undef_F: +; CHECK: # %bb.0: +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> poison, <vscale x 2 x i1> undef, <vscale x 2 x i1> %x, i32 %evl) + ret <vscale x 2 x i1> %a +} + +define <vscale x 2 x i1> @select_unknown_undef_F(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, i32 zeroext %evl) { +; CHECK-LABEL: select_unknown_undef_F: +; CHECK: # %bb.0: +; CHECK-NEXT: vmv1r.v v0, v8 +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> %x, <vscale x 2 x i1> undef, <vscale x 2 x i1> %y, i32 %evl) + ret <vscale x 2 x i1> %a +} + +define <vscale x 2 x i1> @select_unknown_T_undef(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, i32 zeroext %evl) { +; CHECK-LABEL: select_unknown_T_undef: +; CHECK: # %bb.0: +; CHECK-NEXT: vmv1r.v v0, v8 +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, <vscale x 2 x i1> poison, i32 %evl) + ret <vscale x 2 x i1> %a +} + +define <vscale x 2 x i1> @select_false_T_F(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, <vscale x 2 x i1> %z, i32 zeroext %evl) { +; CHECK-LABEL: select_false_T_F: +; CHECK: # %bb.0: +; CHECK-NEXT: vmv1r.v v0, v9 +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> zeroinitializer, <vscale x 2 x i1> %y, <vscale x 2 x i1> %z, i32 %evl) + ret <vscale x 2 x i1> %a +} + +define <vscale x 2 x i1> @select_unknown_T_T(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, i32 zeroext %evl) { +; CHECK-LABEL: select_unknown_T_T: +; CHECK: # %bb.0: +; CHECK-NEXT: vmv1r.v v0, v8 +; CHECK-NEXT: ret + %a = call <vscale x 2 x i1> @llvm.vp.select.nxv2i1(<vscale x 2 x i1> %x, <vscale x 2 x i1> %y, <vscale x 2 x i1> %y, i32 %evl) + ret <vscale x 2 x i1> %a +} |